Key-cutting machine with coordinated positioning and cutting movements

ABSTRACT

A key-cutting device having a vertically and transversely movable key blank support member carrying adjustable gauging elements for presetting the depth of cut to be made on the key blank. The support member is lowered into operative position by a cam operating through a lever or rocker arm having a lost-motion connection with the cam to permit overtravel after the support member has attained the limit of its preselected downward movement. The hand lever which is utilized to operate the cam and lower the support member also serves to advance the cutting tool to traverse the key blank. Spring means engage the support member to both retract it from the anvil surface of the cutting machine and elevate it to an inoperative position in response to completion of each cut on the key blank and retraction of the cutting tool. Traversing movement of the key blank is accomplished through a rack-and-pinion arrangement and appropriately spaced detents.

United States Patent Inventor Nathan S. Lleptz Beachwood, Ohio Appl. No.12,697 Filed Feb. 19, 1970 Patented Jan. 11, 1972 Assignee Curtis NollCorporation Cleveland, Ohio KEY-CUTTING MACHINE WITH COORDINATEDPOSITIONING AND CUTTING MOVEMENTS l 1 Claims, 3 Drawing Figs.

Primary Examiner-Gerald A. Dost Attorney-Isler & Ornstein ABSTRACT: Akey-cutting device having a vertically and transversely movable keyblank support member carrying adjustable gauging elements for presettingthe depth of cut to be made on the key blank. The support member islowered into operative position by a cam operating through a lever orrocker arm having a lost-motion connection with the cam to permitovertravel after the support member has attained the limit of itspreselected downward movement. The hand lever which is utilized tooperate the cam and lower the support member also serves to advance thecutting tool to traverse the key blank. Spring means engage the supportmember to both retract it from the anvil surface of the cutting machineand elevate it to an inoperative position in response to completion ofeach cut on the key blank and retraction of the cutting tool. Traversingmovement of the key blank is accomplished through a rack-and-pinionarrangement and appropriately spaced detents.

PATENTEDJANIHQYZ SHEETIUFZ INVENTOR. NATHAN 5. \-\EPTZ x m TO&NEY5

KEY-CUTTING MACHINE WITH COORDINATED POSITIONING AND CUTTING MOVEMENTSCROSS-REFERENCES TO RELATED APPLICATIONS This application is animprovement upon the subject of my copending application Ser. No.729,281, filed May 15, 1968, and entitled Key Cutting Machine WithPreselected Depth Gauging and now Pat. No. 3,469,636.

BACKGROUND OF THE INVENTION In the field of key-cutting machines thereare basically two distinct varieties for the purpose of cuttingreplacement keys. One of these varieties is broadly denominated as aduplicator" which utilizes an existing cut key as a pattern forreproducing the same sequence of cuts on a suitable key blank. The othervariety of key cutting machine can be broadly denominated as a codecutter" which does not require an existing cut key as a pattern, butinstead utilizes a key or lock number and coded key cuts information toestablish settings on the machine which will provide the desiredsequence of cuts on a suitable key blank. Both varieties can be eithermanually or power operated and can be either partially or fullyautomated.

In my above-mentioned copending patent application, I have disclosed animproved form of code cutter which utilizes a readout" form ofpreselected depth gauging by means of which the entire code sequence ofcuts for the key blank can be preset on the machine before any cuts aremade. The present invention relates to new features and improvedoperating characteristics on the type of code cutter disclosed in theaforesaid copending application.

SUMMARY OF THE INVENTION A code cutter type of key-cutting machinehaving a vertically movable key blank support member operable by alostmotion lever linkage, simultaneously with the actuation of the keycutting tool, to position the key blank support member for a preselecteddepth of cut as predetermined by adjustable gauging surfaces. Yieldableretraction elements engage the Support member for the multifold purposesof elevating the key blank out of the path of movement'ofthe cuttingtool after the cut has been completed, and providing a variable spacingbetween the key blank and the anvil of the machine to accommodate tovariations in the thickness of the key blank, as well as to preventbinding between the cutting tool and the key blank during the retractivemovement ofthe cutting tool.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a view in elevation of thefront end ofa key-cutting machine embodying the features of myinvention.

FIG. 2 is a view in elevation of the side of the aforesaid keycuttingmachine, with portions thereof broken away to show detail.

FIG. 3 is an enlarged fragmentary cross-sectional view taken asindicated on line 3-3 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, thereis shown a key-cutting machine having a frame or body 11 which has, atone end thereof, an upwardly projecting portion or block 12 and at theother end thereof a depending handgrip portion 13. Secured to therearward face of the block 12 is a wear surface or anvil 14 having alongitudinally extending aperture 15 therein which also extends throughthe block 12. Projecting upwardly from the body 11, rearwardly of theanvil 14 is a pillar or post 16 which is surmounted by a finger orupwardly projecting abutment 17.

A sleeve or saddle member 18 is slidably mounted on the post 16 forvertical movement relatively to the body 11. A toothed rack 19 isfixedly secured to the saddle member 18 and serves as a guide rail ortrack for traversing movement ofa key blank support member 20 which isslidably mounted on the rack 19. The support member 20 carries a pinion21 which operatively engages the toothed rack 19 and is manipulated by ahand wheel 22 to effect transverse movement of the support memberrelatively to the rack 19.

The upper portion of the support member is provided with a depth gaugeassembly 23 which can be adjusted to establish a predetermined depth ofcut for each transverse position of the support member. The depth gaugeassembly overlies the abutment or finger 17 which is disposed in thepath of downward movement of the support member and engages the depthgauge assembly to limit the extent of downward movement of the supportmember 20. The forward face of the support member is provided withsuitable means, such as the apertures 24, for detachably receiving andpositioning any one of many different types of key blank carriages S,depending upon the nature and characteristics of the style of key blankK which is mounted on the carriage and is to be cut in the machine 10. Ascrew-operated clamping element 25 is mounted on the support member 20to releasably retain the carriage S and the key blank K in a fixedposition on the support member. A detent spring 26 serves to engageappropriately spaced notches on the carriage S to designate theincremental transverse spacing of the cuts on the key blank.

A cutting tool in the form ofa punch 27 is mounted in the body forslidable longitudinal movement through the post 16 and into the aperture15 so that its cutting edge 28 transverses a portion of the key blank Kwhich is positioned in its path of movement. The punch is provided witha forward extension 29 which rests in the aperture 15 and serves as aguide for the for ward end of the punch during its cutting movement. Therearward end of the punch traverses an upstanding block 30 on the rearof the body 11, which serves as a guide or bearing for that end of thepunch. A coil spring 31, which bears against the rear face of the post16 and bears against a diametrical pin 32 on the punch 27, serves toyieldably maintain the punch in a retracted position with its rearwardend bearing upon the upper end of a force-compounding hand lever 33which is pivotally secured to the body 11 as at 34.

The details and function of the depth gauging assembly, the key blanksupport member, the anvil, the cutting punch and the hand lever are morefully described in my aforesaid copending patten application, thedisclosure of which is incorporated herein by reference.

A rocker arm 35 is pivotally secured to the body 11 rearwardly of thesaddle 18, as at 36. The forward end of the rocker arm is bifurcated toprovide spaced fingers 37 which are movably accommodated and retained inrecesses 38 defined by spaced pairs of projections 39 provided onopposite faces of the saddle member. A flexible element 40 has one endthereof fixedly secured to the rocker arm 35, as at 41, to provide acantilever which extends rearwardly and whose free end is provided withdepending ears 42 in which is jour naled a friction-reducing roller 43.The roller 43 engages a cam surface 44 provided on the upper end'of thehand lever 33. The cam surface has a notch or dwell 45 in which theroller is received and rests when the cutting tool 27 is in itsretracted position. An adjustable set screw 46 is threadedly mounted onthe top wall of the rocker arm 35 and projects downwardly intoengagement with the upper surface of the flexible element 40 at a pointintermediate the ends thereof. By rotating the set screw in onedirection or the other to vary its effective length and,correspondingly, the extent of force or thrust it exerts upon theflexible element, the degree or extent of stiffness or relative rigidityof the flexible element can be adjustably regulated.

A wire-form U-shaped spring 47 is suitably affixed to the rear block 30,as by plate 48, and has its legs extending forwardly into biasingengagement with the undersurface of the rocker arm 35, so as to urge itsforward end upwardly. An ex pansion coil spring 49 extends between theplate 48 and an car 50 on the saddle 18 to normally urge the rack 19into abutment with the front surface of the post 16. When this abutmentcondition exists, the opposing surface 51 of the saddle 18 is spacedfrom the rear face of the post 16 to provide a predetermined clearanceon the order of 0.025 inches. The function and purpose of this clearanceis to accommodate the support member 20 to variations in the thicknessof the key blanks, as will be more fully described hereinafter.

The operation of the cutting machine will now be described. In itsnormal or inoperative position, the punch 27 is retracted and yieldablymaintained in such retracted position by the compression coil spring 31to the extent limited by the abutment of the hand lever 33 with the body11, as at 52. The hand lever is in its forwardmost position. In thisfully retracted position of the punch, its cutting edge 28 is disposedrearwardly of the key blank carried by the carriage S on the supportmember 20, so that the key blank K is positioned forwardly of thecutting edge 28 between it and the plane of the anvil 14. It will beunderstood that, in this inoperative position, the key blank K is notdisposed in the path of cutting movement of the cutting tool 27, as thesupport member 20 is in its fully elevated position where it isyieldably maintained by the urging of the U-spring 47 acting on therocker arm 35. The engagement of the roller43 of the flexible element 40in the dwell portion 45 of the hand lever 33 serves to limit. the extentof upward movement of the rocker arm fingers 37 and the support member20 on the post 16. In this inoperative position, the expansion coilspring 49 yieldably maintains the saddle 18 in itsrearmost position toprovide the previously described clearance between it and the rearwardface of the post 16.

It is assumed that the multiple adjustable elements of the depth gaugingassembly 23 have been prepositioned for the desired sequential depths ofcut and the hand wheel 22 has been rotated to cause traversing movementof the support member 20 to the first detent position of the carriage Swhich represents the first cut to be made on the key blank. In thisposition, the abutment finger 17 is disposed in registry with the pathof movement of the depth gauging element for the first cutting position.

As the hand lever 33 is drawn toward the hand grip 13, it displaces thecutting tool 27 to advance it in opposition to the spring 31 andsimultaneously cams the roller 43 to displace the free end of thecantilever arm 40 upwardly to cause downward movement of the rocker armfingers 37 in an arcuate movement about the pivot point 36, inopposition to the urging of the spring 47. This causes relative downwardmovement of the saddle 18 and the support member 20 until the depthgauge assembly comes into abutment with the upstanding finger 17. Asthis point of abutment defining the lowermost position of the supportmember will vary with the desired depth of cut on the key blank,continued camming displacement of the roller 43 will occur as the handlever 33 is retracted to the limit of its rearward position. However,the lost motion permitted by the flexibility of the cantilever member 40allows for this overtravel of the end of the flexible element, eventhough the pivotal movement of the rocker arm has been arrested prior tothe completion of the full stroke of the hand lever.

When the support member 20 and the key blank K have attained theirpreselected lowermost position, the cutting edge 28 of the punch 27 hasnot yet been moved forwardly sufficiently to engage the key blank,although the key blank is now disposed in the path of advancing movementof the cutting edge. Theoretically, each general style of key blank hasa uniform thickness and its specific carriage S is so dimensioned as toposition the key blank on the support member 20 in such forward positionas to bring it into a plane coincident with the plane of the surface ofthe anvil 14, so that the key blank will be in full surface abutmentwith the face of the anvil when the cutting action occurs. Such fullcontact or abutment of the key blank with the anvil is desirable inobtaining a clean and accurate cutting action of the cutting tool 27, aswell as avoiding or minimizing cocking of the key blank and bindinginterference with the punch during its retractive movement. However, asa practical matter it has been found that there are manufacturingvariations in the thickness of the key blank stock which may increase ordecrease its thickness by as much as 0.010 inches from its nominal orstandard dimension. For this reason, the specific carriages S cannot bedimensioned to dispose the key blank in the desired plane of abutmentwith the anvil face, as allowance must be made for an increase in thestock thickness of the key blank resulting from the aforesaidmanufacturing variations. Therefore, the carriage must be dimensioned sothat even the key blanks which are overly thick will not interfere withthe anvil when the support member is lowered to its operative position.Thus the dim ensional arrangement is such that the key blank which is ofmaximum oversize in thickness will have the most effective abutment withthe anvil. Conversely, those key blanks which are of lesser thickness,such as the standard thickness or the undersized key blanks will bedisposed in a plane spaced from he surface of the anvil and will nothave satisfactory abutment contact, thereby resulting in a poor andinaccurate cut as well as creating the possibility of the cocking of thekey blank due to the pressure of the punch with the resultant bindingeffect and jamming of the punch during its retractive movement. Thesepractical considerations and undesirable consequences are avoided andeliminated by the spring loading of the saddle 18 to provide theabove-described clearance between the saddle and the post 16.

With the spring-loaded arrangement of the saddle the key blank isnormally maintained rearwardly of the plane of the anvil face regardlessof the manufacturing variations of the range normally encountered in thethickness of the key blank. The clearance space of 0.025 inches betweenthe saddle and the post 16 is large enough to compensate for the maximumthickness variation from normal which can be expected in any key blank.It will be noted that when the fingers 37 pivot downwardly to lower thesupport member 20, they also have a forward vector of movement which, tosome extent, displaces the saddle forwardly toward the rear face of thepost 16 as the support member reaches its lower limit of position.However, the primary forward displacement of the saddle element 18occurs as a result of the advancing engagement of the cutting edge 28with the key blank K which forces the key blank into full surfaceabutment with the anvil 14 in opposition to the action of the spring 49.The yieldably maintained clearance between the saddle and the post issufficient to permit this forward displacement.

As soon as the hand lever is initially released, the coil spring 31causes the cutting member 27 to retract and simultaneously the spring 47urges the saddle and support member upwardly out of the path ofretractive movement of the punch while the spring 49 urges the saddle l8and support member 20 rearwardly. This movement of the key blank, thoughinitially only light, is sufficient to prevent any binding or jammingbetween the key blank and the retracting punch. In this manner, theyieldable clearance provided by the spring-loaded saddle accommodates toand compensates for the manufacturing variations in the thickness of thevarious key blank styles and eliminates the disadvantageous consequenceswhich have heretofore been encountered as a result of such variations.

As the hand lever is further released, the cutting tool 27 and thesupport member 20 are restored to their initial positions at which thedescribed operating cycle was started. The hand I wheel 22 is nowrotated to cause traversing movement of the support member 20 to thedetent position defining the second cutting position of the key blankand the operating cycle is repeated with the abutment finger 17 nowbeing disposed in the path of movement of another of the adjustablegauging surfaces of the depth gauge assembly 23. The operative cycle isrepeated until all the required cuts have been made. If a duplicatesecond replacement key is to be made, the cut key blank is replaced withanother key blank of the same style and the operative cycle is repeated,without the necessity of changing any of the previously set depth gaugesettings on the depth gauge assembly 23.

It will be understood that the degree or quality of flexibility of thecantilever element 41 is a matter of critical sensitivity. If theelement 41 is excessively flexible. it will not be rigid enough toovercome the action of the U-spring 47 as the roller 43 is displaced bythe cam 44, and the element 41 will simply flex or deform withoutcausing the desired downward movement of the rocker arm fingers 37. Onthe other hand, if the cantilever element 41 is overly rigid or stiff,it will not permit the necessary lost motion or overtravel in relationto the rotation of the rocker arm 35. This will result in an inabilityto complete the complete rearward stroke of the hand lever 33 to fullyadvance the cutting tool 27 after the limit of downward movement of thesupport member has been achieved. if the hand lever 33 were to be forcedbeyond this point, injury or deformation to one or more of the operatingparts would have to occur. Although the cantilever element 41 could bemanufactured to strict specifications of desired flexibility for thepurpose intended, such a procedure would result in an excessivelyexorbitant manufacturing cost for the element. Furthermore, even thoughthe degree of flexibility of the element 41 were initially satisfactoryand within the critical limits desired, it would eventually becomeoverly flexible through fatigue and wear in use. These problems areovercome by the previously described arrangement of the adjusting screw46 to 'vary the degree of operative stiffness or flexibility of thecantilever element 40 as conditions warrant. This arrangement permitsaccommodation to the wear and fatigue which the element 40 encountersthrough use as well as minimizing the initial manufacturing cost of theelement.

It is to be understood that the form of my invention, herewith shown anddescribed, is to be taken as a preferred example of the same, and thatvarious changes in the shape, size and arrangement of parts may beresorted to, without departing from the spirit of my invention, or thecope of the subjoined claims.

Having thus described my invention, I claim:

1. In a key-cutting device, the combination of a body, a movable cuttingtool carried by said body, a vertically and transversely movable keyblank support member mounted on said body for positioning a key blank inselected cutting relationship to said cutting tool, first meansyieldably maintaining said support member in a position out of saidcutting relationship, second means for actuating said cutting tool, andthird means responsive to operation of said second means for mov ingsaid support member into said cutting relationship in opposition to saidfirst means.

2. A combination as defined in claim 1, wherein said second meanscomprises a hand lever, and said third means comprises a lever assemblyengaging said support member and actuated by said hand lever.

3. A combination as defined in claim 2, wherein said cutting tool isslidably movable on said body into and out of said cutting relationship.

4. A combination as defined in claim 3, wherein said first meansdisplaces said support member in response to movement ofsaid cuttingtool out of said cutting relationship.

5. A combination as defined in claim 2, wherein said lever assemblycomprises a rocker arm pivotally secured to said body and having one endthereof engaging said support member, cam means provided on said handlever, and a lostmotion connection provided on said rocker arm andengaged by said cam means to effect displacement thereof.

6. A combination as defined in claim 5, wherein said lostmotionconnection comprises a flexible element secured to said rocker arm anddefining the other end thereof.

7. A combination as defined in claim 6, including means carried by saidrocker arm and engaging said flexible element for adjusting thestiffness of said element.

8. A combination as defined in claim 5, including adjustable gaugingmeans carried by said support member for selectively limiting saidrocker arm induced movement of said support member. I

9. A combination as defined in claim 8, wherein said first meansmaintains said support member in a vertically elevated position, andsaid rocker arm induced movement is vertically downward.

10. In a key-cutting device, the combination of a body, an anvilprovided on said body, a cutting tool mounted on said body for movementinto and out ofsaid anvil, a key blank support member mounted on saidbody for selective movement of a key blank into the path of advancingmovement of said cutting tool, whereby said cutting tool presses saidkey blank into coplanar abutment against said anvil, and means forwithdrawing said key blank support member from said anvilengagingposition in response to retractive movement of said cutting tool.

11. A combination as defined in claim 10, wherein said means is a springelement engaging said support member and yieldably maintaining saidsupport member in spaced retracted relationship to the plane of saidanvil.

1. In a key-cutting device, the combination of a body, a movable cuttingtool carried by said body, a vertically and transversely movable keyblank support member mounted on said body for positioning a key blank inselected cutting relationship to said cutting tool, first meansyieldably maintaining said support member in a position out of saidcutting relationship, second means for actuating said cutting tool, andthird means responsive to operation of said second means for moving saidsupport member into said cutting relationship in opposition to saidfirst means.
 2. A combination as defined in claim 1, wherein said secondmeans comprises a hand lever, and said third means comprises a leverassembly engaging said support member and actuated by said hand lever.3. A combination as defined in claim 2, wherein said cutting tool isslidably movable on said body into and out of said cutting relationship.4. A combination as defined in claim 3, wherein said first meansdisplaces said support member in response to movement of said cuttingtool out of said cutting relationship.
 5. A combination as defined inclaim 2, wherein said lever assembly comprises a rocker arm pivotallysecured to said body and having one end thereof engaging said supportmember, cam means provided on said hand lever, and a lost-motionconnection provided on said rocker arm and engaged by said cam means toeffect displacement thereof.
 6. A combination as defined in claim 5,wherein said lost-motion connection comprises a flexible element securedto said rocker arm and defining the other end thereof.
 7. A combinationas defined in claim 6, including means carried by said rocker arm andengaging said flexible element for adjusting the stiffness of saidelement.
 8. A combination as defined in claim 5, including adjustablegauging means carried by said support member for selectively limitingsaid rocker arm induced movement of said support member.
 9. Acombination as defined in claim 8, wherein said first means maintainssaid support member in a vertically elevated position, and said rockerarm induced movement is vertically downward.
 10. In a key-cuttingdevice, the combination of a body, an anvil provided on said body, acutting tool mounted on said body for movement into and out of saidanvil, a key blank support member mounted on said body for selectivemovement of a key blank into the path of advancing movement of saidcutting tool, whereby said cutting tool presses said key blank intocoplanar abutment against said anvil, and means for withdrawing said keyblank support member from said anvil-engaging position in response toretractive movement of said cutting tool.
 11. A combination as definedin claim 10, wherein said means is a spring element engaging saidsupport member and yieldably maintaining said support member in spacedretracted relationship to the plane of said anvil.